According to the previous reports, obesity is resulted from that assimilated calorie is much than consumption. The excessive calorie is stored as triglyceride (hereinafter referred to as TG) in adipose tissue and thereby accumulated in pancreas, liver, skeleton muscle. The accumulation of triglyceride in these indicated organs causes obesity and metabolic syndrome such as cardiovascular diseases, hypertension, hyperlipidemia and type II diabetes. Currently, WHO has been categorized obesity as a chronic illness disease. In Taiwan, the nutritional health reports from 2004 to 2008 had suggested that the excessive nutrition would cause the occurrence of many chronic illness diseases.
The obesity could be cured by various therapy approaches such as exercise, calorie control and surgery. However, eating out is the common dietary habit of people in the rush modem world. Therefore, the rush modem life style makes it difficult to low body weight through exercise and calorie control. Furthermore, the cost of the surgeries for lowing body weight such as cosmetic surgery and laparoscopic gastric bypass surgery are quite expansive. In addition to the expansive cost, the surgeries may bring some uncertain risk for the safety of patients. Some pharmaceutical approaches such as metabolic stimulus, appetite inhibitor and starch blocker are approached to low the body weight. However, intake of these drugs for a long term will bring some side effects to the subjects. In order to avoid the side effects of these available drugs, many investigations have suggested that the nature compounds and extracts are capable of lowing body weight through inhibiting appetite or accelerating the metabolism of energy. For example, caffeine accelerates energy metabolism through inhibition of phosphodiesterase activity to increase the cyclic adenosine monophosphate. The extract of Hoodia Cactus is capable of suppressing the appetite; the extract of Prunella vulgaris is able to be the starch blocker through inhibiting the enzyme activity of salivary amylase; the extract of Semen plantaginis is capable of lowing the concentration of TG in blood by accelerating the lipid metabolism.
Because these indicated natural extracts do not achieve the purpose for lowing weight through controlling the cell cycle of adipocytes, inhibiting adipocytes differentiation, promoting the lipolysis in adipocytes, the functions of these extracts are not efficient and obvious. Therefore, the current investigations have focused on development of new natural compounds for controlling behavior of adipocytes or suppressing the lipogenesis to efficiently suppress the lipid accumulation and obesity.